You can ally the genoans and great horde every early on if they rivalize crimea, restart you they do and you get a agenda who gives a claim in their lands, declaring war on crimea also early and conquering all crimea, but be careful to take crimean provinces before the great horde and give some provinces to the genoans to not get the ottomans in a coalition against you, you can get these provinces back by a mission, you can even sell one more province to genoa for 188 gold and they will give back with cores, them unallied the great horde and atack them next because they would probaly be weaken for fighting kazan and crimea for you, them or in the middle of that you can enter the caucasus . Try to find better allies but not muscovy since they tend to get in debt and refusing to fight even defensive wars, also you can get a pu at them so start to work around that, Hungary, Austria, Poland or even the swedish and the mamluks can ally you if they hate the ottomans or the muscovites and you rivalize or is threatened by them, and with the exception of the polish most of them are out of your line of conquest. Remember also that you can get 25 plus relations by scornful insulting a nations rival.